Spectrometer specimen holder



y 1960 v w'. c. KEESAER 2,939,007

SPECTROMETER SPECIMEN HOLDER Filed Sept. 29, 1958 2 Sheets-Sheet 1 +70 PWER SUPPY r0 com me PUMP IN VEN T OR.

fi Clg azz ATTOQALEY W. C. KE ESAER SPECTROMETER SPECIMEN HOLDER Ma sl, 1960 2 Sheets-Sheet 2 Filed Sept. 29, 1958 p m R m R 0 f O T T N% 1 m A m6 I w W a W W i Y i W x W W a I i.-...... flvwy W 6% 2,939,007 SPECTROMETER SPECIMEN HOLDER William C. Keesaer, Flint, Mich., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware r Filed Sept. 29, 1958, Ser. No. 763,912

Claims. (Cl. 250- 52) This invention relates to spectrometers and more particularly to abulk speciment holder fora spectrometer to cut up and destroy larger parts in order to get a specimen small enough to fit in the specimen retaining apparatus. For example, a large gear which is to be analyzed by spectrometry and which is too large to be retained in the apparatus, must have a portion cut from it small destroying the gear for any further use, i

The device in which this invention is embodied comprises a specimen receiving table mounted over the emitting tube and above the remainder of the spectrometer apparatus. The table is not limited to the siz e of the part to be analyzed, as long as thepar t can be placed over a central port in the table through which the emitted rays may be deflected. Pedestals are provided for, thepspeetrometer analyzing crystal mounting and for the target mounting in order to properly align the crystal and the target with the ray emissions, With a device of this kind it is not necessary to cut up and destroy production parts in order to obtain a sample of a size to be readily analyzed. Thus, a much more economical operation is provi ded and one that makes the specimen mounting much more accessible to the equipment operator. Greater versatility is also provided, and increased adaptability to production processes.

In the drawings: a

enough to fit in the spectrometer specimen holder, thus Figire l is a perspective view ofa typical spectrometer showing the addition of the-specimen table and mounting pedestals.

Figure 2 is an Figure 1 showing the location ofthe various parts.

Figure 3 is a plan view of the mounting table of Figure 2 taken substantially along the line 3--3 of Figure 2 and looking in the direction of the arrows.

Figure 4 is a side view of the mounting table of Figure 2 with parts broken away and in section and taken sub stantially along the line 44 of Figure 3.

Referring more particularly to the drawings, a conventional spectrometer apparatus is shown in Figure 1. The apparatus is mounted on a suitable support, such as a table 10, and consists generally of a base 12 having the sliding arcuate scale 14 suitably mounted and geared thereon. As in conventional spectrometer apparatus, a means is provided for rotating the scale 14 and such means are generally placed within the base 12. Mounted on the scale 14 is a collimating tube 16 which passes the emitted rays to the preamplifier assembly 18, from which the signals are passed to suitable receiving apparatus. A

elevational view of the .deviceshown in t fienassembly 18.

2,939,007 Ice Patented May 31, 1960 control box 20, located on the table 10 adjacent the base 12, contains the controls for the motivating means, consisting generally of an on-otf switch 22, a manual or automatic control 24 and a speed control 26.

An analyzing crystal 28 is secured in a mounting illus-;

trated generally by the numeral 30, the mounting being suitably secured to the arm 32. The arm. 32 is geared with respect to the scale 14 such that rotation of the scale also imparts rotation to the arm 3-2 and the crystal mounting apparatus 30.

An X-ray tube 34 is mounted adjacent the machine and has suitable electric leads 36 and 38 from a power supply. The specimen mounting assembly, illustrated generally by the numeral 40, may be mounted either on the machine base 12 or on the table 10 and is secured over the X-ray tube 34. Q p p As may be seen in Figure 2, thebracket assembly 42 is illustrated as being secured to the table 10 as by bolts 44. The bracket extends upwardly as at 46 and angularly asat 48 in order to secure the mounting table 50 in an optimum position over the X-ray tube 34. The table 5.0 may be welded, as at '52, to the supporting bracket exten: sion 48. t r

In referring to Figure 2, it may be seen that the X-ray emissions from the X-ray tube, illustrated by a dashed and dotted line 54, (are emitted'from the X-ray tube 34 through thetable 50 and deflected from the specimen-56;. The deflected rays pass through a beam tunnel 58 which passes the desired emissions to the analyzing crystal 28 andfrorn there to the collimating tube 16 and the ampli- The X-ray tube 34is secured in a cooling jacket 60 which :has passages 62 formed therein and on either :side of the,,tube; =A U-shaped portion of copper tubing 64 connects the passages 62 at the end of the X-ra-y tube '34 to allow circulation .throughthe jacket. Coolant fluid is supplied to thepassages 62 by the conduits 66 which con+ meet -with a suitable cooling purnp. A bottom portion .68 ofx hc cooling .jacketis secured to the cooling jacket 6% withasuitable gasket 70 therebetween. The entire assembly is secured to the specimen table 50, asbybolts 72.

A port'74, referring to Figures 3 and 4, is formed cen trally of thegspecimen table 50 and located 'directly over the X r ay tube 34 such that emissions from the X-ray tub e will pass ,directly through the port 74. The specimen 56-;to be ana1'yzed, isplaced overthe port 74 to receive the direet emissions f rom; the tube. in order :to accommodate the conventional beam tunnel 5 8, which sorts out the undesiredrX-ray emissions deflected from the specimen 56, a stepped block 576 is secured to the underside of the specimen table .50. An opening 78 through the block 76 allows passage of deflected emissions to the beam tunnel58, step 80,-is provided in the block 76 to receivepreeis'ion spacer blocks 82 to properly set the beam'tu'nnel 58. "The 'beam tunnel andthe spacer blocks are secured to the block 76, as by bolts 84. i

In order to securely hold the specimen 56 on the upper side of the table .50, a clamping assembly is provided which consists of side rails 86, secured to the upper side of the table 50, and the sliding cross arm 88. The rails 86 are of box-like construction with a longitudinal slot in the top surface to receive T-bolts 90, or the like, which secure the cross arm 88. The rails are secured to the specimen table by bolts or machine screws 92. A spring clip 94 is secured to the cross arm 88 by a bolt 96 and may be placed over a portion of the specimen 56, as shown in dashed and dotted lines in Figure 4-, to retain the specimen in the proper position over the port 74.

In order to prevent stray X-ray emissions from passing to the atmosphere, a cover 98 is hinged to the table 50 by hinges 100. The cover 98 has the inner surfaces thereof lined with lead 102, or some suitable emission absorbing material. The cover is adapted to close over the specimen table 50 and is actuated by a handle 104.

As a safety precaution, and to prevent X-ray emission permits emission to begin.

In order to accommodate specimens of a size larger 1 than may be retained within the cover 98 it is possible for the machine operator to actuate the micro-switches 106 with the cover open. However, for safety purposes, it is preferred that the switches be operated only-by the 'cover 98.

To place the analyzing crystal 28 in its proper vertical relation with respect to the beam-tunnel 58 a pedestal is placed between the arm 32 and the mounting 30. The pedestal consists of upper and lower plates 112 and 114,

analyzing crystal and an emission counter and comprising a specimen table having an X-ray portlocated substantially centrally therein, a bracket mounted adjacent said spectrometer and supporting said table in spaced angular relation over said X-ray tube, a cooling jacket surrounding said X-ray tube and secured to the underside of said table adjacent said port therein, a beam tunnel mounting block secured to the underside of said table to retain a beam tunnel in position to transmit X-ray emissions from; said X-ray tube when deflected by a specimen placed over said X-ray port, a lead-lined cover hingedlysecured to said table to enclose the upper side of said table when a specimen is placed thereon, and a switch secured to said bracket adjacent-the edge of said cover and operatively connected to said X-ray tube and actuated by said cover to prevent X-ray emission from said X-ray tube when said cover is in an open position.

4. A holder for a specimen to be examined in an X-ray spectrometerhaving an X-ray emittingtube, an analyzing crystal and mounting, and an emission counting tube and mounting and comprising a table having a port cen' trally disposed therein, means for mounting said table over said X-ray tube such that emissions from said tube connected by a plurality of columns 116. Similary,;the

collimating tube 16 and the amplifier assembly 18 are raised to the proper vertical level with respect to the beam tunnel 58 and the analyzing crystal 28 by a pedestal consisting of upper and lower plates 118 and 120 con nected by a plurality of columns 122. The usual crystal tuning knob 124 is provided in the mounting 30 for fine adjustments of the angularity of the analyzing crystal 28, It may thus be seen that a specimen mounting assembly for a spectrometer has been shown which does not limit 7 the size of the specimen to be analyzed and does not require that the specimen be taken from a'larger part, destroying the usefulness of the larger part. It is not intended to limit the invention by the foregoing description'but only by the scope of the appended claims. I claim: I

1. A holder for a bulk specimen tobe examined in X-ray spectrometer having an X-ray tube and an analyzing crystal and a'target and comprising a table having a port therein, "means supportingsaid table in'angnlar relation over said X-ray tube, cooling means for said X-ray tube secured to the underside of-said table, beam tunnel retaining means secured to the undersidefof said table and adjacent said port, a cover hingedly secured to v said table to enclose the upper'surfaee of said table when cludes clamping means on the upper surface of said table to retain a specimen thereon the correct position over saidport. V 1 g I 3. A holder for a specimen'to be enaminedrin an X-ray spectrometer having an X-ray emitting tube, an

pass through said port, clamping means on the upper side of said table for retaining a specimen in analyzing position over saidport, and switch means adjacent said table for allowing X-ray emissions from said X-ray tube only at the will of an operator.

5. Aholder for a specimen to be examined in an'X-ray spectrometer having an X-ray emitting tube, an analyzing crystal and mounting, and an emission counting tube and mounting and comprising a table having a port centrally disposed therein, means for mounting said' table over said X-ray tube such that emissions from said tube pass through said port, means 'for'retaining abeam tunnel adjacent the underside of said table and adjacent said port therein, first pedestal means for supporting said analyzing crystal and mounting and raising said crystal and mounting to the correct vertical relationtwith respect to said table such that X-ray emissions from said X-ray tube deflected from said specimen will impinge on said analyzing crystal, second pedestal means supporting said emission counting tube and mounting and placing said tube and mounting in a proper vertical relation with respect, to said analyzing crystal, clamping means on the upper side of said tablefor retaining a specimen in analyzing position over said port, and switch means 'adja cent said table for allowing X-ray emissions from said X-ray tube only at the will ofan operator. 1

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